For many manufacturing, maintenance, and repair projects, drilling is an indispensible part of the operation. Under some circumstances, drilling can become hazardous to the person conducting the drilling, the workpiece, and/or the equipments and environment surrounding the drilling site. If essential safety devices cannot be provided, or if proper safety procedures cannot be followed, accidents during drilling may happen, causing significant damages and threatening the worker's wellbeing.
One example for hazardous drilling operations is drilling conducted during electrical work. The electricians are sometimes required to drill on the metal housing of switchgears, which in many instances have to stay “live”—with the electricity still on during the drilling process. Such requirements are not rare, especially for the maintenance and repair work conducted for companies, factories and hospitals, where the continuous provision of electricity is essential. However, the metal shavings and debris resulted from drilling are very hard to collect and such shavings and debris may disperse into the live switchgear, causing short-circuiting or even explosion. Most electricians use make-shift arrangements to collect the shavings and debris. For example, one worker may reach inside the housing of live gear and hold a cardboard box under the drill site while another worker drills through the top. However, such temporary solutions are far from complete and fully effective.
Some devices and systems have been developed to address the danger associated with drilling debris. These designs, however, show shortcomings in one aspect or another. For example, U.S. Pat. No. 6,974,048 ('048 patent) discloses a safety tool that includes magnets and an outer non-conductive sheath encompassing an inner bag. A purpose of the tool is to provide safety for the operator while drilling or cutting into electrical/electronic enclosures, such as switchgear. The tool is constructed so that an operator can perform a task while preventing any conductive debris caused by this task to come in contact with any electrical parts. The top portion of the tool magnetically attaches to the inside of the switchgear structure. The bottom portion of the tool, which is coupled to the top portion by the non-conductive sheath, collects and magnetically contains the debris, such as shavings from drilling into the structure. The debris is collected in the inner bag, which can easily be removed from the tool for disposal of the debris.
This design of the '048 patent, however, has at least two significant disadvantages. First, while much all of the debris is generated on the drilling surface where drilling is initiated, such debris is not properly collected. It should be noted that the majority of the shavings stay at the drilling side and the design taught by the '048 patent does not address these shavings at all. The device disclosed by the '048 patent only collects the shavings after the drill bit has penetrated the workpiece. The shavings on the side of the drill are not collected and these shavings have the potential to cause significant damage to the surrounding equipment as well as the worker himself/herself. More importantly, the tool disclosed by the '048 patent requires the worker to place his/her arm into the housing of live gear to attach the tool to the inner surface of the housing. Similar action is also required to remove the tool from inside the housing of live gear. Such attachment/removal processes significantly increase the chance that the worker would be electrocuted, accidentally drop the bag full of shavings/slugs into the gear, or come in contact with energized parts while holding the bag full of shavings. Therefore, the design by the '048 patent is both unreliable and unsafe.
The hazards of drilling into live electrical equipment involve at least (1) the danger of metal shavings and the slug created by the hole saw entering the housing of the gear during the drilling process and after the drilling process is completed from the drilling side; (2) the danger of the hole saw being released from the drill chuck during the drilling process and falling into the live equipment; (3) the danger of a worker reaching into the live equipment to place equipment inside the housing of live gear under the drilling area to catch debris and removing it, and (4) the danger of dropping the conductive metal shavings accidentally inside the housing of live gear once such shavings are collected.
The current invention addresses all the concerns herein discussed and properly collects all the shavings generated in a drilling process without requiring a worker to reach inside the house of live gear. The devices taught by the current invention may be used in various types of drilling operations and are particularly useful for drilling conducted during electrical work. In summary, various implements are known in the art, but fail to address all of the problems solved by the invention described herein. The preferred embodiments of this invention are illustrated in the accompanying drawings and will be described in more detail herein below.